summaryrefslogtreecommitdiff
path: root/kernel/resource.c
diff options
context:
space:
mode:
authorTejun Heo <htejun@gmail.com>2007-01-20 16:00:26 +0900
committerJeff Garzik <jeff@garzik.org>2007-02-09 17:39:36 -0500
commit9ac7849e35f705830f7b016ff272b0ff1f7ff759 (patch)
tree7f17cdff87e154937a15cc2ec8da9b4e6018ce8e /kernel/resource.c
parent77a527eadb425b60db3f5f0aae6a4c51c38e35e5 (diff)
downloadlwn-9ac7849e35f705830f7b016ff272b0ff1f7ff759.tar.gz
lwn-9ac7849e35f705830f7b016ff272b0ff1f7ff759.zip
devres: device resource management
Implement device resource management, in short, devres. A device driver can allocate arbirary size of devres data which is associated with a release function. On driver detach, release function is invoked on the devres data, then, devres data is freed. devreses are typed by associated release functions. Some devreses are better represented by single instance of the type while others need multiple instances sharing the same release function. Both usages are supported. devreses can be grouped using devres group such that a device driver can easily release acquired resources halfway through initialization or selectively release resources (e.g. resources for port 1 out of 4 ports). This patch adds devres core including documentation and the following managed interfaces. * alloc/free : devm_kzalloc(), devm_kzfree() * IO region : devm_request_region(), devm_release_region() * IRQ : devm_request_irq(), devm_free_irq() * DMA : dmam_alloc_coherent(), dmam_free_coherent(), dmam_declare_coherent_memory(), dmam_pool_create(), dmam_pool_destroy() * PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed() * iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(), devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(), pcim_iomap(), pcim_iounmap() Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'kernel/resource.c')
-rw-r--r--kernel/resource.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 7b9a497419d9..2a3f88636580 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/device.h>
#include <asm/io.h>
@@ -618,6 +619,67 @@ void __release_region(struct resource *parent, resource_size_t start,
EXPORT_SYMBOL(__release_region);
/*
+ * Managed region resource
+ */
+struct region_devres {
+ struct resource *parent;
+ resource_size_t start;
+ resource_size_t n;
+};
+
+static void devm_region_release(struct device *dev, void *res)
+{
+ struct region_devres *this = res;
+
+ __release_region(this->parent, this->start, this->n);
+}
+
+static int devm_region_match(struct device *dev, void *res, void *match_data)
+{
+ struct region_devres *this = res, *match = match_data;
+
+ return this->parent == match->parent &&
+ this->start == match->start && this->n == match->n;
+}
+
+struct resource * __devm_request_region(struct device *dev,
+ struct resource *parent, resource_size_t start,
+ resource_size_t n, const char *name)
+{
+ struct region_devres *dr = NULL;
+ struct resource *res;
+
+ dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
+ GFP_KERNEL);
+ if (!dr)
+ return NULL;
+
+ dr->parent = parent;
+ dr->start = start;
+ dr->n = n;
+
+ res = __request_region(parent, start, n, name);
+ if (res)
+ devres_add(dev, dr);
+ else
+ devres_free(dr);
+
+ return res;
+}
+EXPORT_SYMBOL(__devm_request_region);
+
+void __devm_release_region(struct device *dev, struct resource *parent,
+ resource_size_t start, resource_size_t n)
+{
+ struct region_devres match_data = { parent, start, n };
+
+ __release_region(parent, start, n);
+ WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
+ &match_data));
+}
+EXPORT_SYMBOL(__devm_release_region);
+
+/*
* Called from init/main.c to reserve IO ports.
*/
#define MAXRESERVE 4